Mineral oil compositions and processes of preparing the same



Patented Apr. 16, 1940 UNITED STATES PATENT OFFICE MINERAL OILCOMPOSITIONS AND PROC- ESSES OF PREPARING THE SAME Anderson W. Ralstonand Everett .1. Hofiman,

Chicago, 111., assignors to Armour and Company, Chicago, 111., acorporation of Illinois No Drawing. Application October 14, 1938 SerialNo. 235,095

7 Claims.

a metallic chloride acylating catalyst, hydrolyz-- ing the intermediatemetallic chloride complex The pour point of an oil is in part directlyrelated to the amount of parailln wax in the oil and it is customary todewax the oil both for the recovery of usable paraffin and for loweringthe pour point of the oil. Even after drastic dewaxing operations thefinal lubricating oil does not always have as low a pour'point as theart desires. Parafiin wax itself, however, has lubrieatingcharacteristics, and prior workers have sought to keep some of the waxin the oil by so modifying the pour point of the oil that in spite ofits wax content the oil can be used for lubricating at low temperatures.This has been accomplished in recent years by adding to the oilsubstances to which the name pour point depressors has been given. Quitea few substances for this purpose have been discovered. Theoretically itis assumed that a pour point depressor inhibits crystallization of theparaffln wax in the oil and thus prevents the oil, when subjected to'lowtemperatures, from forming a kind of sludge or slush of relativelylarge'wax crystals occupying the entire volume of the oil and occludingliquid oil within the network of crystals.

Atthe present time condensation products between chlorinatedparaflinsand aromatics are used to a considerable extent as pour pointdepressors. Products of this nature are much less efflcient in theiractions than compounds de-. d5 scribed'in this invention. In additionthey contribute nothing to the oiliness of the lubricant to which theyare added which is markedly different from our products.

In all instances the amount-of pour point de- ISO pressor added isrelatively small. The quantities generally average a fraction of apercent based that they add oiliness to the oil. The substances which weuse can be generically defined as acylated indenes wherein the acylgroup contains at least twelve carbon atoms. These acylated indenes arenew materials in themselves and are the subject matter of the Ralston,Vander Wal and Bauer application Serial No. 228,260 filed September 2,1938. These compounds are prepared, broadly speaking, by reactingindene, or one of its polymers, with a fatty acid chloride having atleast twelve carbon atoms in the presence of an acylating catalyst, suchas aluminum chloride. This reaction results in the formation of anintermediate complex containing the catalyst which is thereafterhydrolyzed to free it of catalyst, and the final product recovered. Thusthe preparation of these acylated indenes-follows closely the acylationof other aromatic hydrocarbons by the Friedel-Crafts synthesis. Butduring the acylation of the indene the indene polymerizes. Or it ispossible that the indene is first acylated and thereafter the acylderivative polymerizes. In any event, the final product is an acylatedand polymerized indene. Or, toput it more definitely, it is apolymerized indene containing acyl groups having twelve or more carbonatoms.

In the preparation of these pour point depressors any fatty acidchloride having twelve or more carbon atoms can be used. These can beeither saturated or unsaturated, or they can be fatty acid chloridesmade from fatty acids prepared by the oxidation of paraffln wax or otherhydrocarbons yielding fatty acids on oxidation. Mixtures of two or moredifferent fatty acid chlorides can be used as the acylating agent. Thisgives us final products of mixed character and very complexconstitution. Indeed the pour point depressor effect of our products maypossibly be due to the complex nature of them. As fatty acid chlorideswe can use lauryl, myrlstyl, palmityl, stearyl, oleyl, linoleyl andlinolenyl chlorides, these being the more usual ones.

In broad aspects,.the fatty acid chloride is added to a suspension ofthe acylating catalyst, such as aluminum chloride, in an inert solvent,and to this mixture indene dissolved in an inert solvent is added. Theproportions of fatty acid chloride to indene can vary over wide limitsas we have found by experiment. This probably means that so long as theindene polymer contains at least one acyl group the product has .-pourpoint depressor characteristics. But more than one acyl group can bepresent in the final product. V

point depressors are made from fatty acid chicrides of at least twelvecarbon atoms and in-= denes.

Example Twenty grams of aluminum chloride are sus= pended in 50 cc. oftetrachloroethane in a three-= necked flask equipped with a stirrer,dropping funnel and thermometer. To this is added, rap= idly, 30 gramsof stearyl chloride, the temperature being held below C. during theaddition.

15.7 grams of a 74 percent solution of indene in tetrachloroethane areadded over a period of one and one-half hours. The temperature variesbetween about 25 C. and C. during the addition. The temperature is thenkept at about C. to C. for about one hour. The resulting reactionproduct is then hydrolyzed by admixing with ice and the solvents removedby steam distillation. The product is dissolved in ether, washed wellwith water and the ether solution dried with sodium sulfate. The etheris then removed under a vacuum.

In precisely the same manner other acylated indenes are prepared as morefully disclosed in the aforesaid application.

The final product is semi-solid and plastic, and resinous in character.It dissolves readily in mineral oils in proportions used for pour pointdepressing.

We shall now indicate by way of example how our products function whenadded to lubricating oils.

In the following examples the oils designated as 1, 2 and 3 are threedifferent kinds of lubricating oils in common commercial use. In thefollowing examples where we refer to indene solution (74%) we havereference to the solution given in the foregoing example of thecharacteristic way of making our compounds. The

examples also indicate the pour point of the original oil and the pourpoint of the 011 after the addition of our pour point depressor Example1 A compound prepared from 15.7 parts of indene solution (74%) and 30parts of stearyl chloride is added to the following lubricating oils.0.5%

0.5% of a compound prepared from 15.7 parts of indene solution (74%)parts of stearyl chloride is added to the oils with the followingresults:

Saybo Pout point, F. Oil viseos ity Original Treated Seconds We shallnow give an example of how our pour Example 3 0.5% of a product preparedby the reaction of 15.7 parts of indene solution (74%) and 30'parts ofoleyl chloride is added to the oils with the following results:

saybolt I Pour point, F. Oil viscosity at Original Treated SecondsEwample 4 0.5% of a product prepared by the actionbf 15.7 parts ofindene solution (74%) and 30 parts of linolenyl chloride is added to theoils with the following results:

saybolt Pour point, F. Oil viscof ity at 100 F Original Treated Thusfrom the above examples it is apparent that our pour point depressorsare markedly effective for the purpose intended, a pour point loweringof as much as 55 F. being obtained. Our pour point depressors areespecially effective on oils having rather high pour points, thusindicating the marked ability of our compounds to preventcrystallization of the wax.

Similar results are obtained when other fatty acid chlorides havingtwelve or. more carbon atoms are used. The amount of pour pointdepressor can'vary over wide limits. Noticeable improvement in pourpoint lowering is obtained when only 0.1% of our products is added.Larger amounts, up to 2% or 3% can also be added but much greateramounts, such as 10% or 15% are not necessary in order to obtain asubstantial pour point lowering.

In addition to the property of lowering the pour point of the mineraloils these products also decrease the heat generated during runningfriction. The oils were testedin an apparatus described by Ralston,Hofl'man and Stephens, found in National Petroleum News, dated November3, 1937. The addition of 0.5% of the product used in Example 1 showed adifference of 24.5 F. in temperature rise after one and onehalf hoursbetween an original and a treated oil.

In the appended claims we use the langauge an indene to include theindene dimers,

' trimers or tetramers as well as indene itself since the indene thereofis the essential polymerizing component. r

Although we have referred more particularly to the use of our acylatedindene materials with lubricating oils it is apparent that they can alsobe-added to lubricating greases where it is desirable to reduce the heatof friction or to prevent the grease from assuming a relatively hard,

non-flowing state when subjected to a cold en- 7 vironment. -Whenpreparing such greases we can first dissolve the pour point depressor inthe lubricating oil and then make a lubricating grease therefrom .in theusual way.

Having thus described our invention, what we claim is:

l. A mineral oil containing, as a pour point depressor, an acylatedindene, the acyl group having at least .twelve carbon atoms.

2. A mineral 011 containing, as a pour point depressor, a stearylatedindene.

3. A mineral oil containing, as .a pour point depressor, an acylatedindene polymer wherein the acyl group contains at least twelve carbonatoms.

4. A mineral oil containing, as a pour point depressor, a stearylatedindene polymer.

5. Amineral oil containing. as a pour point depressor, the productobtained by reacting indene with a fatty acid chloride having at leasttwelve carbon'atoms in the presence of an acylating catalyst, andrecovering a catalyst-free product.

6. A mineral oil containing, as a pour point depressor, the product ofreacting an indene with stearyl chloride in the presence of an acylatingcatalyst and recovering a catalyst-free product.

'7. The process of depressing the pour point of a mineral oil whichcomprises adding to the oil the products resulting from reacting anindene with a fatty acid chloride having at least twelve carbon atoms inthe presence of an acylating catalyst and recovering a catalyst-freeproduct.

. ANDERSON W. RALSTON.

EVERETT J. HOFFMAN.

